The sympathetic nervous system in heart failure revisited.

Several attempts have been made, by the scientific community, to develop a unifying hypothesis that explains the clinical syndrome of heart failure (HF). The currently widely accepted neurohormonal model has substituted the cardiorenal and the cardiocirculatory models, which focused on salt-water retention and low cardiac output/peripheral vasoconstriction, respectively. According to the neurohormonal model, HF with eccentric left ventricular (LV) hypertrophy (LVH) (systolic HF or HF with reduced LV ejection fraction [LVEF] or HFrEF) develops and progresses because endogenous neurohormonal systems, predominantly the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS), exhibit prolonged activation following the initial heart injury exerting deleterious hemodynamic and direct nonhemodynamic cardiovascular effects. However, there is evidence to suggest that SNS overactivity often preexists HF development due to its association with HF risk factors, is also present in HF with preserved LVEF (diastolic HF or HFpEF), and that it is linked to immune/inflammatory factors. Furthermore, SNS activity in HF may be augmented by coexisting noncardiac morbidities and modified by genetic factors and demographics. The purpose of this paper is to provide a contemporary overview of the complex associations between SNS overactivity and the development and progression of HF, summarize the underlying mechanisms, and discuss the clinical implications as they relate to therapeutic interventions mitigating SNS overactivity.

Conduction system pacing: how far are we from the "electrical" bypass?

Conduction system pacing is an alternative practice to conventional right ventricular apical pacing. It is a method that maintains physiologic ventricular activation, based on a correct pathophysiological basis, in which the pacing lead bypasses the lesion of the electrical fibers and the electrical impulse transmits through the intact adjacent conduction system. For this reason, it might be reasonably characterized by the term "electrical bypass" compared to the coronary artery bypass in revascularization therapy. In this review, reference is made to the sequence of events in which conventional right ventricular pacing may cause adverse outcomes. Furthermore, there is a reference to alternative strategies and pacing sites. Interest focuses on the modalities for which there are data from the literature, namely for the right ventricular (RV) septal pacing, the His bundle pacing (HBP), and the left bundle branch pacing (LBBP). A more extensive reference is about the HBP, for which there are the most updated data. We analyze the considerations that limit HBP-wide application in three axes, and we also present the data for the implantation and follow-up of these patients. The indications with their most important studies to date are then described in detail, not only in their undoubtedly positive findings but also in their weak aspects, because of which this pacing mode has not yet received a strong recommendation for implementation. Finally, there is a report on LBBP, focusing mainly on its points of differentiation from HBP.

Association between Ranolazine, Ischemic Preconditioning, and Cardioprotection in Patients Undergoing Scheduled Percutaneous Coronary Intervention.

Background and Objectives: Remote ischemic preconditioning (RIPC) has demonstrated efficacy in protecting against myocardial ischemia-reperfusion injury when applied before percutaneous coronary revascularization. Ranolazine, an anti-ischemic drug, has been utilized to minimize ischemic events in chronic angina patients. However, there is a lack of trials exploring the combined effects of ranolazine pretreatment and RIPC in patients undergoing percutaneous coronary interventions (PCIs). Materials and Methods: The present study is a prospective study which enrolled 150 patients scheduled for nonemergent percutaneous coronary revascularization. Three groups were formed: a control group undergoing only PCIs, an RIPC group with RIPC applied to either upper limb before the PCI (preconditioning group), and a group with RIPC before the PCI along with prior ranolazine treatment for stable angina (ranolazine group). Statistical analyses, including ANOVAs and Kruskal-Wallis tests, were conducted, with the Bonferroni correction for type I errors. A repeated-measures ANOVA assessed the changes in serum enzyme levels (SGOT, LDH, CRP, CPK, CK-MB, troponin I) over the follow-up. Statistical significance was set at p < 0.05. Results: The ranolazine group showed (A) significantly lower troponin I level increases compared to the control group for up to 24 h, (B) significantly lower CPK levels after 4, 10, and 24 h compared to the preconditioning group (p = 0.020, p = 0.020, and p = 0.019, respectively) and significantly lower CPK levels compared to the control group after 10 h (p = 0.050), and (C) significantly lower CK-MB levels after 10 h compared to the control group (p = 0.050). Conclusions: This study suggests that combining RIPC before scheduled coronary procedures with ranolazine pretreatment may be linked to reduced ischemia induction, as evidenced by lower myocardial enzyme levels.

The impact of delirium on clinical and functional outcomes in hospitalized patients with acute coronary syndrome.

BACKGROUND: Delirium, which is prevalent in critical care settings, remains underexplored in acute coronary syndrome (ACS) patients in the cardiac intensive care unit (CICU). AIMS: To investigate the prevalence and clinical significance of delirium in patients with ACS admitted to the CICU. STUDY DESIGN: A prospective study (n = 106, mean age 74.2 ± 5.7 years) assessed delirium using the confusion assessment method-intensive care unit (CAM-ICU) tool in 21.7% of ACS patients during their CICU stay. Baseline characteristics, geriatric conditions and clinical procedures were compared between delirious and nondelirious patients. The outcomes included in-hospital mortality, 30-day and 6-month mortality, acute adverse events and length of CICU stay and hospital stay (LOS). RESULTS: Delirious patients who were older and had a higher incidence of coronary artery disease underwent more complex procedures (e.g., pacemaker placement). Multivariate analysis identified central venous catheter insertion, urinary catheterization and benzodiazepine use as independent predictors of delirium. Delirium was correlated with prolonged LOS (p < .001) and increased in-hospital, 30-day and 6-month mortality (p < .001). CONCLUSIONS: Delirium in ACS patients in the CICU extends hospitalization and increases in-hospital, 30-day and 6-month mortality. Early recognition and targeted interventions are crucial for mitigating adverse outcomes in this high-risk population. RELEVANCE TO CLINICAL PRACTICE: This study highlights the critical impact of delirium on outcomes in hospitalized patients with ACS in the CICU. Delirium, often overlooked in ACS management, significantly extends hospitalization and increases mortality rates. Nurses and physicians must be vigilant in identifying delirium early, particularly in older ACS patients or those with comorbidities. Recognizing independent predictors such as catheterization and benzodiazepine use allows for targeted interventions to reduce delirium incidence. Integrating routine delirium assessments and preventive strategies into ACS management protocols can improve outcomes, optimize resource utilization and enhance overall patient care in the CICU setting.

Long-Term Prognostic Value of Automated Measurements in Nuclear Cardiology: Comparisons with Expert Scoring.

Background and Objectives: Automated methods for the analysis of myocardial perfusion studies have been incorporated into clinical practice, but they are currently used as adjuncts to the visual interpretation. We aimed to investigate the role of automated measurements of summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) as long-term prognostic markers of morbidity and mortality, in comparison to the prognostic value of expert reading. Materials and Methods: The study was conducted at the Nuclear Medicine Laboratory of the University of Thessaly, in Larissa, Greece. A total of 378 consecutive patients with known or suspected coronary artery disease were enrolled in the study. All participants were referred to our laboratory for the performance of stress/rest myocardial perfusion single photon emission computed tomography. Automated measurements of SSS, SRS, and SDS were obtained by Emory Cardiac Toolbox (ECTb (Version 3.0), Emory University, Atlanta, GA, USA), Myovation (MYO, Xeleris version 3.05, GE Healthcare, Chicago, IL, USA), and Quantitative Perfusion SPECT (QPS (Version 4.0), Cedars-Sinai Medical Center, Los Angeles, CA, USA) software packages. Follow-up data were recorded after phone contacts, as well as through review of hospital records. Results: Expert scoring of SSS and SDS had significantly greater prognostic ability in comparison to all software packages (p < 0.001 for all comparisons). Similarly, ECTb-obtained SRS measurements had significantly lower prognostic ability in comparison to expert scoring (p < 0.001), while expert scoring of SRS showed significantly higher prognostic ability compared to MYO (p = 0.018) and QPS (p < 0.001). Conclusions: Despite the useful contribution of automated analyses in the interpretation of myocardial perfusion studies, expert reading should continue to have a crucial role, not only in clinical decision making, but also in the assessment of prognosis.

Therapeutic augmentation of NO-sGC-cGMP signalling: lessons learned from pulmonary arterial hypertension and heart failure.

The nitric oxide (NO)-guanylate cyclase (GC)-cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal function. Phosphodiesterase-5 inhibitors (PDE-5i) inhibit cGMP degradation, whereas both soluble guanylate cyclase (sGC) stimulators and sGC activators directly increase sGC. PDE-5i (e.g. sildenafil, tadalafil) and sGC stimulators (e.g. riociguat, vericiguat) have been extensively used in pulmonary artery hypertension (PAH) and heart failure (HF). PDE-5i have also been used in end-stage HF before and after left ventricular (LV) assist device (LVAD) implantation. Augmentation of NO-GC-cGMP signalling with PDE-5i causes selective pulmonary vasodilation, which is highly effective in PAH but may have controversial, potentially adverse effects in HF, including pre-LVAD implant due to device unmasking of PDE-5i-induced RV dysfunction. In contrast, retrospective analyses have demonstrated that PDE-5i have beneficial effects when initiated post LVAD implant due to the improved haemodynamics of the supported LV and the pleiotropic actions of these compounds. sGC stimulators, in turn, are effective both in PAH and in HF due to their balanced pulmonary and systemic vasodilation, and as such they are preferable to PDE-5i if the use of a pulmonary vasodilator is needed in HF patients, including those listed for LVAD implantation. Regarding the effectiveness of PDE-5i and sGC stimulators when initiated post LVAD implant, these two groups of compounds should be tested in a randomized control trial.

Left ventricular hypertrophy and sudden cardiac death.

Sudden cardiac death (SCD) is among the leading causes of death worldwide, and it remains a public health problem, as it involves young subjects. Current guideline-directed risk stratification for primary prevention is largely based on left ventricular (LV) ejection fraction (LVEF), and preventive strategies such as implantation of a cardiac defibrillator (ICD) are justified only for documented low LVEF (i.e., ≤ 35%). Unfortunately, only a small percentage of primary prevention ICDs, implanted on the basis of a low LVEF, will deliver life-saving therapies on an annual basis. On the other hand, the vast majority of patients that experience SCD have LVEF > 35%, which is clamoring for better understanding of the underlying mechanisms. It is mandatory that additional variables be considered, both independently and in combination with the EF, to improve SCD risk prediction. LV hypertrophy (LVH) is a strong independent risk factor for SCD regardless of the etiology and the severity of symptoms. Concentric and eccentric LV hypertrophy, and even earlier concentric remodeling without hypertrophy, are all associated with increased risk of SCD. In this paper, we summarize the physiology and physiopathology of LVH, review the epidemiological evidence supporting the association between LVH and SCD, briefly discuss the mechanisms linking LVH with SCD, and emphasize the need to evaluate LV geometry as a potential risk stratification tool regardless of the LVEF.

Automated Analysis vs. Expert Reading in Nuclear Cardiology: Correlations with the Angiographic Score.

Background and Objectives: Myocardial perfusion imaging (MPI) has an important role in the non-invasive investigation of coronary artery disease. The interpretation of MPI studies is mainly based on the visual evaluation of the reconstructed images, while automated quantitation methods may add useful data for each patient. However, little evidence is currently available regarding the actual incremental clinical diagnostic performance of automated MPI analysis. In the present study, we aimed to assess the correlation between automated measurements of Summed Stress Score (SSS), Summed Rest Score (SRS) and Summed Difference Score (SDS), with the corresponding expert reading values, using coronary angiography as the gold standard. Materials and Methods: The study was conducted at the Nuclear Medicine Laboratory of the University Hospital of Larissa, Larissa, Greece, οver an one-year period (January 2019-January 2020). 306 patients, with known or suspected coronary artery disease, were enrolled in the study. Each participant underwent a coronary angiography, prior to or after the scintigraphic study (within a three-month period). Either symptom-limited treadmill test, or pharmacologic testing using adenosine or regadenoson, was performed in all participants, and the scintigraphic studies were carried out using technetium 99m (99mTc) tetrofosmin (one-day stress/rest protocol). Coronary angiographies were scored according to a 4-point scoring system (angiographic score; O: normal study, 1: one-vessel disease, 2: two-vessel disease, 3: three-vessel disease). Moreover, automated measurements of SSS, SRS and SDS were derived by three widely available software packages (Emory Cardiac Toolbox, Myovation, Quantitative Perfusion SPECT). Results: Interclass Correlation Coefficients of SSS, SRS and SDS between expert reading and software packages were moderate to excellent. Visually defined SSS, SRS and SDS were significantly correlated with the corresponding results of all software packages. However, visually defined SSS, SRS and SDS were more strongly correlated with the angiographic score, indicating a better performance of expert reading when compared to automated analysis. Conclusions: Based on our results, visual evaluation continues to have a crucial role for the interpretation of MPI images. Software packages can provide automated measurements of several parameters, particularly contributing to the investigation of cases with ambiguous scintigraphic findings.

Adult congenital heart disease with pulmonary arterial hypertension: mechanisms and management.

Adult congenital heart disease (ACHD) encompasses a range of structural cardiac abnormalities present before birth attributable to abnormal foetal cardiac development. The pulmonary circulation of patients with ACHD and intracardiac or extracardiac defects is often exposed to increased blood flow and occasionally to systemic pressures. Depending on the location and magnitude of the defect as well as the time of surgical correction, the patient with ACHD is at risk of developing pulmonary arterial hypertension (PAH), which dramatically increases morbidity and mortality. It is encouraging that therapies applied in idiopathic PAH and significantly improve outcome are also effective in ACHD-related PAH (ACHD-PAH). This review summarizes the challenges encountered in the diagnosis and management of ACHD-PAH.

Acutely decompensated versus acute heart failure: two different entities.

Heart failure (HF) has been classified in chronic HF (CHF) and acute HF (AHF). The latter has been subdivided in acutely decompensated chronic HF (ADCHF) defined as the deterioration of preexisting CHF and de novo AHF defined as the rapid development of new symptoms and signs of HF that requires urgent medical attention. However, ADCHF and de novo AHF have fundamental pathophysiological differences. Most importantly, the typical illness trajectory of HF, which is similar to that of other chronic organ diseases including lung, renal, and liver failure, features a gradual decline, with acute episodes usually related to disease evolution followed by partial recovery. Thus, ADCHF should be considered part of the natural history of CHF and renamed CHF exacerbation (CHFE) in accordance with the appropriate terminology used in chronic obstructive pulmonary disease. AHF, in turn, should include only acute de novo HF. The clinical implications of this paradigm shift will be in CHFE the change in focus from in-hospital to optimal ambulatory CHF management aiming at primary and secondary CHFE prevention, while in AHF, the institution of measures for in-hospital limitation of cardiac injury and prevention or retardation of symptomatic CHF development.

Coexisting Morbidities in Heart Failure: No Robust Interaction with the Left Ventricular Ejection Fraction.

PURPOSE OF REVIEW: Heart failure (HF) patients often present with multiple coexisting morbidities. In this review, we contend that coexisting morbidities are highly prevalent and clinically important regardless of the left ventricular ejection fraction (LVEF). RECENT FINDINGS: Multimorbidity is prevalent in the ambulatory subjects of the community and increases with age. Differences in the prevalence of coexisting morbidities between HF with preserved LVEF (> 50%), mid-range LVEF (40-50%), and reduced LVEF (< 40%) are either not demonstrable or whenever present are small and unrelated to morbidity and mortality. The constellation of coexisting morbidities together with the disease modifiers (age, sex, genes, other) defines the HF phenotype and outcome. There is no robust evidence supporting an interaction in HF patients between the prevalence and clinical significance of coexisting morbidities and the LVEF.

Impact of renin-angiotensin-aldosterone system polymorphisms on myocardial perfusion: Correlations with myocardial single photon emission computed tomography-derived parameters.

BACKGROUND: Renin-angiotensin-aldosterone system (RAAS) has an important role in atherosclerosis. We investigated the effects of six RAAS gene polymorphisms on myocardial perfusion. METHODS AND RESULTS: We examined 810 patients with known or suspected coronary artery disease (CAD) using stress-rest myocardial single-photon emission computed tomography. Summed stress score (SSS), summed rest score (SRS), summed difference score (SDS), transient ischemic dilation (TID), and lung/heart ratio (LHR) were recorded. The following gene polymorphisms were investigated: angiotensin-converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen (AGT) M235T and T174M, angiotensin II type 1 receptor (AT1R) A1166C, renin (REN) C5312T, and angiotensin II type 2 receptor (AT2R) C3123A. The heterozygotes or homozygotes on ACE D allele were 7.54 times more likely to have abnormal SSS, while the AGT (T174M) heterozygotes were 5.19 times more likely to have abnormal SSS. The homozygotes of ACE D had significantly higher values on TID and LHR, while the AGT (T174M) heterozygotes had higher values on TID. The AT1R heterozygotes had greater odds for having SSS ≥ 3. The patients carried AT1R homozygosity of C allele had significantly higher values on TID, while heterozygotes of AT1R had significantly higher values on LHR. CONCLUSIONS: Among the polymorphisms investigated, ACE D allele had the strongest association with abnormal myocardial perfusion.

SPECT and PET in ischemic heart failure.

Heart failure is a common clinical syndrome associated with significant morbidity and mortality worldwide. Ischemic heart disease is the leading cause of heart failure, at least in the industrialized countries. Proper diagnosis of the syndrome and management of patients with heart failure require anatomical and functional information obtained through various imaging modalities. Nuclear cardiology techniques play a main role in the evaluation of heart failure. Myocardial single photon emission computed tomography (SPECT) with thallium-201 or technetium-99 m labelled tracers offer valuable data regarding ventricular function, myocardial perfusion, viability, and intraventricular synchronism. Moreover, positron emission tomography (PET) permits accurate evaluation of myocardial perfusion, metabolism, and viability, providing high-quality images and the ability of quantitative analysis. As these imaging techniques assess different parameters of cardiac structure and function, variations of sensitivity and specificity have been reported among them. In addition, the role of SPECT and PET guided therapy remains controversial. In this comprehensive review, we address these controversies and report the advances in patient's investigation with SPECT and PET in ischemic heart failure. Furthermore, we present the innovations in technology that are expected to strengthen the role of nuclear cardiology modalities in the investigation of heart failure.

Red blood cell distribution width as a prognostic marker in patients with heart failure and diabetes mellitus.

BACKGROUND: Red blood cell distribution width (RDW) is an established prognostic marker in acute and chronic heart failure (HF). Recent studies have pointed out a link among RDW, diabetes mellitus (DM) and inflammation. We sought to investigate the prognostic value and longitudinal pattern of RDW in patients with concomitant HF and DM, which remains unknown. METHODS: A total of 218 patients (71 diabetics) who presented with acute HF had RDW measured at admission, discharge and 4, 8 and 12 months post-discharge. The study endpoint was all-cause mortality or rehospitalization for HF during 1-year follow-up. RESULTS: The study endpoint was met in 33 patients (46.5%) with DM and in 54 patients (36.7%) without DM. RDW at admission was associated with higher event rate both in HF patients with and without DM (adjusted HR: 1.349, p = 0.002, 95% CI 1.120-1.624 and adjusted HR: 1.142, p = 0.033, 95% CI 1.011-1.291 respectively). In addition, a significant interaction was found between diabetes and RDW longitudinal changes (ßinteraction = -0.002; SE = 0.001; p = 0.042). CONCLUSIONS: Despite the similar prognostic significance of RDW in diabetic and non-diabetic HF patients regarding the study endpoint, longitudinal changes were found to be significantly different between these two groups of HF patients. This might be due to the higher inflammatory burden that diabetic HF patients carry and may provide new insights to the pathophysiological mechanism of RDW increase in HF, which remains unknown.

Latest updates on structure and recommendations of cardiac rehabilitation programs in chronic heart failure.

Chronic heart failure (HF) is a clinical syndrome with high morbidity and mortality worldwide. Cardiac rehabilitation (CR) is a medically supervised program designed to maintain or improve cardiovascular health of people living with HF, recommended by both American and European guidelines. A CR program consists of a multispecialty group including physicians, nurses, physiotherapists, trainers, nutritionists, and psychologists with the common purpose of improving functional capacity and quality of life of chronic HF patients. Physical activity, lifestyle, and psychological support are core components of a successful CR program. CR has been shown to be beneficial in all ejection fraction categories in HF and most patients, who are stable under medication, are capable of participating. An individualized exercise prescription should be developed on the basis of a baseline evaluation in all patients. The main modalities of exercise training are aerobic exercise and muscle strength training of different intensity and frequency. It is important to set the appropriate clinical outcomes from the beginning, in order to assess the effectiveness of a CR program. There are still significant limitations that prevent patients from participating in these programs and need to be solved. A significant limitation is the generally low quality of research in CR and the presence of negative trials, such as the rehabilitation after myocardial infarction trial, where comprehensive rehabilitation following myocardial infraction had no important effect on mortality, morbidity, risk factors, or health-related quality of life or activity. In the present editorial, we present all the updated knowledge and recommendations in CR programs.

Heart Transplantation.

Heart transplantation (HTx) remains the last therapeutic resort for patients with advanced heart failure. The present work is a clinically focused review discussing current issues in heart transplantation. Several factors have been associated with the outcome of HTx, such as ABO and HLA compatibility, graft size, ischemic time, age, infections, and the cause of death, as well as imaging and laboratory tests. In 2018, UNOS changed the organ allocation policy for HTx. The aim of this change was to prioritize patients with a more severe clinical condition resulting in a reduction in mortality of people on the waiting list. Advanced heart failure and resistant angina are among the main indications of HTx, whereas active infection, peripheral vascular disease, malignancies, and increased body mass index (BMI) are important contraindications. The main complications of HTx include graft rejection, graft angiopathy, primary graft failure, infection, neoplasms, and retransplantation. Recent advances in the field of HTx include the first two porcine-to-human xenotransplantations, the inclusion of hepatitis C donors, donation after circulatory death, novel monitoring for acute cellular rejection and antibody-mediated rejection, and advances in donor heart preservation and transportation. Lastly, novel immunosuppression therapies such as daratumumab, belatacept, IL 6 directed therapy, and IgG endopeptidase have shown promising results.

Back to the basics: The need for an etiological classification of chronic heart failure.

The left ventricular (LV) ejection fraction (LVEF), despite its severe limitations, has had an epicentral role in heart failure (HF) classification, management, and risk stratification for decades. The major argument favoring the LVEF based HF classification has been that it defines groups of patients in which treatment is effective. However, this reasoning has recently collapsed, since medical treatment with neurohormonal inhibitors, has proved beneficial in most HF patients regardless of the LVEF. In addition, there has been compelling evidence, that the LVEF provides poor guidance for device treatment of chronic HF (implantation of cardioverter defibrillator, cardiac resynchronization therapy) since sudden cardiac death may occur and cardiac dyssynchronization may be disastrous in all HF patients. The same holds true for LV assist device implantation, in which the LVEF has been used as a surrogate for LV size. In this review article we update the evidence questioning the use of LVEF-based HF classification and argue that guidance of chronic HF treatment should transition to more contemporary concepts. Specifically, we propose an etiologic chronic HF classification predominantly based on epidemiological data, which will be foundational for further higher resolution phenotyping in the emerging era of precision medicine.

Artificial Intelligence in Heart Failure: Friend or Foe?

In recent times, there have been notable changes in cardiovascular medicine, propelled by the swift advancements in artificial intelligence (AI). The present work provides an overview of the current applications and challenges of AI in the field of heart failure. It emphasizes the "garbage in, garbage out" issue, where AI systems can produce inaccurate results with skewed data. The discussion covers issues in heart failure diagnostic algorithms, particularly discrepancies between existing models. Concerns about the reliance on the left ventricular ejection fraction (LVEF) for classification and treatment are highlighted, showcasing differences in current scientific perceptions. This review also delves into challenges in implementing AI, including variable considerations and biases in training data. It underscores the limitations of current AI models in real-world scenarios and the difficulty in interpreting their predictions, contributing to limited physician trust in AI-based models. The overarching suggestion is that AI can be a valuable tool in clinicians' hands for treating heart failure patients, as far as existing medical inaccuracies have been addressed before integrating AI into these frameworks.

Assessment of Myocardial Viability in Ischemic Cardiomyopathy With Reduced Left Ventricular Function Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: We aim to provide a comprehensive review of the current state of knowledge of myocardial viability assessment in patients undergoing coronary artery bypass grafting (CABG), with a focus on the clinical markers of viability for each imaging modality. We also compare mortality between patients with viable myocardium and those without viability who undergo CABG. METHODS: A systematic database search with meta-analysis was conducted of comparative original articles (both observations and randomized controlled studies) of patients undergoing CABG with either viable or nonviable myocardium, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to 2022. Imaging modalities included were dobutamine stress echocardiography (DSE), cardiac magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET). RESULTS: A total of 17 studies incorporating a total of 2317 patients were included. Across all imaging modalities, the relative risk of death post-CABG was reduced in patients with versus without viability (random-effects model: odds ratio: 0.42; 95% confidence interval: 0.29-0.61; p < 0.001). Imaging for myocardial viability has significant clinical implications as it can affect the accuracy of the diagnosis, guide treatment decisions, and predict patient outcomes. Generally, based on local availability and expertise, either SPECT or DSE should be considered as the first step in evaluating viability, while PET or CMR would provide further evaluation of transmurality, perfusion metabolism, and extent of scar tissue. CONCLUSION: The assessment of myocardial viability is an essential component of preoperative evaluation in patients with ischemic heart disease undergoing surgical revascularization. Careful patient selection and individualized assessment of viability remain paramount.

Pneumococcal and Influenza Vaccination Coverage in Patients with Heart Failure: A Systematic Review.

Background/Objectives: As heart failure (HF) patients face increased vulnerability to respiratory infections, optimizing pneumococcal and influenza vaccination coverage becomes pivotal for mitigating additional health risks and reducing hospitalizations, morbidity, and mortality rates within this population. In this specific subpopulation of patients, vaccination coverage for pneumococcal and influenza holds heightened significance compared to other vaccines due to their susceptibility to respiratory infections, which can exacerbate existing cardiovascular conditions and lead to severe complications or even death. However, despite the recognized benefits, vaccination coverage among HF patients remains below expectations. The aim of the present systematic review was to assess the vaccination coverage for influenza and pneumococcus in HF patients from 2005 to 2023 and the vaccination's effects on survival and hospitalizations. Methods: The authors developed the protocol of the review in accordance with the PRISMA guidelines, and the search was performed in databases including PubMed and Scopus. After the initial search, 851 studies were found in PubMed Library and 1961 in Scopus (total of 2812 studies). Results: After the initial evaluation, 23 publications were finally included in the analysis. The total study population consisted of 6,093,497 participants. Regarding the influenza vaccine, vaccination coverage ranged from low rates of 2.5% to very high rates of 97%, while the respective pneumococcal vaccination coverage ranged from 20% to 84.6%. Most studies demonstrated a beneficial effect of vaccination on survival and hospitalizations. Conclusions: The present systematic review study showed a wide variety of vaccination coverage among patients with heart failure.